This invention relates to the surgical arts, and more particularly to apparatus and method for inserting pacemaker electrodes, catheters and similar devices into an internal organ or cavity of the human body.
The field of medical technology has experienced unprecedented developments in the last several decades. Some of the most dramatic advances in the medical field have occurred in the understanding and control of the human heart. The development of the pacemaker has solved some of the previous problems of heart disease and has extended the lives of thousands of patients.
In the past, the surgical implant of a pacemaker and permanent pacemaker electrode required approximately one to two hours. This surgical procedure was previously done by sectioning through the tissue layers of the patient down to the cephalic vein. An incision was made in the cephalic vein and the electrode tip inserted through the incision and through the vein into the right ventricle of the heart. The electrode was then tied to the body tissue and a second surface incision made for receiving the pacemaker pulse generator. The permanent electrode was connected to the pulse generator by a special plug-receptacle combination, and the pacemaker then was implanted within the patient.
The cephalic vein is located beneath the layers of the pectoralis muscle on the chest wall. Many times a large physical incision and a considerable amount of dissection is required to isolate the cephalic vein. Not infrequently, the cephalic vein is too small to accommodate the size of state-of-the-art pacemaker electrodes. In such a case, more extensive dissection must be made in following the cephalic vein to its origin. The cephalic vein extends beneath the clavicle, running ultimately to the subclavian vein.
It is also well known to insert temporary pacemaker electrodes into a patient's heart through the subclavian vein, using a surgical needle or conventional sheath introducer. The needle is introduced into a patient and the electrode tip is inserted through a center passage in the needle to enter an organ of the patient. The other end of the electrode is temporarily connected to an electronic device or the like.
Permanent pacemaker electrodes generally have an electrode tip on one end and an electrode plug, or hub, on the opposite end. Accordingly, a permanent pacemaker electrode cannot be inserted through a needle since the needle cannot be removed over the electrode plug.
In my U.S. Pat. No. 4,166,469 referred to above, I teach an apparatus and method for introducing a permanent pacemaker electrode into the heart through the subclavian vein by employing a sleeve and introducer combination, in which the sleeve has a slit, or weakened line, almost to the forward end of the sleeve. The unslit portion of the forward end prevents the sleeve from crimping as the sleeve passes through the hard tissue underneath the clavicle in the vicinity of the subclavian vein. Once the forward end of the sleeve is inside the subclavian vein, the electrode is passed through the sleeve and splits the unslit portion of the forward end. The sleeve may then be removed by gently sliding it out of the vein and peeling it off the electrode. If the unslit portion of the sleeve is not split during passage of the electrode down the sleeve, then the unslit portion may be easily slit as the sleeve is being peeled away from the electrode.
In my early work with respect to the apparatus and method described in my U.S. Pat. No. 4,166,469, I found that it was not desirable to slit the sleeve along its entire length, because a sleeve with a slit along its entire length tends to buckle or crimp around the slit at the forward end as it passes through the hard tissue layer surrounding the subclavian vein. Any structural deformity in the sleeve, such as a crimp, can tear the wall of the vein and injure the patient. Prior art which teaches sleeves pre-slit along the entire length include U.S. Pat. Nos. 3,459,184 and 3,185,152 to Ring.
There have also been suggestions in the literature for introducing permanent pacemaker electrodes through an unslit sleeve, and thereafter slitting the sleeve with the scalpel. See, for example, an article written by Drs. Friesen, et al., the Canadian Journal of Surgery, Volume 20, page 131, March, 1977; and Vellani, et al., British Heart Journal, Volume 31, page 106, 1969. However, in my early work, I found that the use of a scalpel in close proximity to the electrode created an unnecessary risk of damage to the insulation surrounding the electrode.
It has been recognized that electrode introduction through the subclavian vein gives rise to a potential risk of air embolism unless appropriate precautions are taken. The above-referenced article by Drs. Friesen, et al. disclose one solution to this potential problem which relies on careful breathing instructions to the patient. Frequently, however, pacemaker implant patients are elderly and are unable to follow the necessary breathing instructions.
In the split sleeve introducer described in my co-pending patent application, the sleeve slides independently of the introducer. There is a natural tendency to slide the sleeve forward from the introducer, as both structures are being inserted into the vein. If the sleeve is slid sufficiently forward, it is possible to move the sleeve an undesirable distance into the vein.
The use of the subclavian vein for the introduction of pacemaker electrodes is discussed in the following references: Mobin-Uddin, et al., Journal of Thoracic and Card. Surgery, pages 545-548 (1967); Jachuck, et al., British Journal of Surgery, Volume 61, pages 373-376 (1974); Pacemaker Technology, page 29 (1975); Modern Cardiac Pacing, page 78; Ahnlund, et al., Annals of the Scandanavian Cardiology Congress, Copenhagen, 1976; Sterz, et al.; Wien. Med. Wschr. 126, 28-31 (1976); Sterz, et al., Z. Kardiol., Volume 66, pages 726-728 (1977); and Torresani, et al., Stimucoeur, Medical Supplement No. 21, Spring, 1978. Each of the above references also makes reference to earlier works of interest.